4. PARTS OF HUMANEAR
Outer Ear (pinna and ear
canal)
Middle Ear(Ear Drum,
Ossicles, Oval Window)
Inner Ear(semi-circular
canal,cochlea,auditory
nerve)
5. OUTER EAR
Pinna-The visible part of the outer ear. It collects sound and directs it into the outer ear canal.
Ear Canal- The tube through which sound travels to the eardrum
Outer Layer Of Eardrum- (tympanic membrane) vibrates when sound
waves reach it
6. MIDDLE EAR
EARDRUM
Also called the tympanic membrane or
myringa.
It is a thin (8-10 mm in diameter), cone-shaped
membrane.
EARDRUM: separates the external ear from
the middle ear.
7. The oval window
The oval window is a membrane covering the
entrance to the cochlea in the inner ear.
When the sound waves are transmitted from the
eardrum to the oval window, the middle ear is
functioning as an Acoustic Transformer
(increasing the efficiency of sound) amplifying the
sound waves before they move on into the inner ear.
The pressure of the sound waves on the oval window
is some 20 times higher than on the eardrum.
8. Bones of the Middle Ear
Hamme
r
(Malleus
)
Stirrup
(Stapes)
Anvil
(Incus
)
These are the smallest
bones in our body.
Together, they’re about the
size of an orange seed.
11. HowSound Travels in the Middle Ear
When sound waves reach the middle ear, they cause the
eardrum to vibrate.
This vibration then causes the three bones to vibrate.
These vibrations are transformed into
longitudinal/pressure waves in the middle ear.
12. THE INNER EAR
Two main
parts:
Cochlea
Auditory
Nerve
The Inner Ear Is The Innermost Part Of
The Ear.
13. The inner ear structure called the cochlea is a
snail-shell like structure divided into three
fluid-filled parts.
Two are canals for the transmission of
pressure and in the third is the sensitive organ
of Corti, which detects pressure impulses and
responds with electrical impulses which
travel along the auditory nerve to the brain.
The Cochlea
Contains approximately 300,000 hair cells.
14. The Auditory Nerve
The cochlear (auditory ) nerve carries auditory sensory information
from the cochlea of the inner ear directly to the brain.
Fail to follow frequencies above 3 kHz.
15. CONT…
The tiny hair cells of the cochlea are set in motion
by vibrations.
The vibrations stimulate tiny nerve cells.
The nerve cells then send signals along the auditory nerve
to the brain
16. A sound is not actually
heard until the brain
receives and processes
these signals.